The electroluminescent device may convert electrical energy to optical energy. The common structure of electroluminescent devices includes a transparent anode, a light-emitting layer and a cathode arranged on a transparent substrate. In order to improve the efficiency of organic electroluminescent light emitting device and reduce the turn-on voltage of the electroluminescent device, conventionally, a variety of other features layers, for example, an electrode surface modification layer, carrier injection layer, a carrier transporting layer, the barrier layer and the buffer layer, may be arranged between the electrode and the light emitting layer. The carrier injection layer is typically electron injection layer or hole injection layer, and a carrier transporting layer is typically an electron transport layer or a hole transport layer. With the increase of various functions of the film, the manufacturing process of the electroluminescent devices becomes more difficult and higher costs may be involved.
Conventionally, electroluminescent devices, especially organic electroluminescent device, are usually made by dry and wet production. Dry methods, such as vapor deposition and sputtering, may easily include multi-layer device structure to obtain better device performance, but fine mask and high vacuum equipment are needed. Material utilization is low, which may waste a lot of material, and thus results in high production costs. Wet preparation processes, such as electrochemical deposition method, a spin coating method and ink jet printing method,are simple, high material utilization, and easy to continuous production. But it is difficult to prepare a multi-layer device structure, and the light emitting efficiency is low. Among them, electrochemical deposition technique adopts organic molecules with electrochemical activity. The oxidation and the reductive coupling reactions occur at the interfaces between the electrode/solution to form polymer film. The method is characterized by attributes such as simple and low cost. The outlook, thickness, aggregation structure, etc. of the films may be configured by electrodeposition method and conditions. Usually, the functional layer is directly deposited on the anode of the electroluminescent device. However, after one functional layer is electrically deposited, the second functional layer cannot contact with the anode, and thus it is difficult to manufacture good electrically deposited film and it is difficult to manufacture the electroluminescent device having a plurality of functional layer, which results in a bad light emitting efficiency.